4HP22 trans issues/maintenance

[Auzeras 28]

I've got a new filter and plan to change the trans fluid, although not all of it, just top off what comes out with the filter as part of maintenance and to try fix an annoying hesitation issue.

Car will hesitate when moving from a start, hill starts also give it a tendency to almost stall out. I'm hoping filter is clogged somewhat and the fluid is old (level is correct by the way) but I thought I'd check before committing new fluid and time to see what the more experienced thought. Does this sound like an old fluid/filter induced issue or more of a mechanical trans issue? Should I really commit a weekend to rebuilding the valve body instead of just an hour or so for the filter?

Current fluid colour is a reddish brown which I interpret to be simply old. Doesn't have much of a smell, neither burnt or sweet.

Thanks for any input.

[yng_750 247]

I didnt think valve body rebuilds were a diy.

[Eagle 1528]

I doubt the filter would be clogged. They are just a mesh screen in these so ive always just cleaned them out and reused them.

Id just change the fluid and see what happens, regular ATF cost is cheap and easy to do with dipstick.

[Auzeras 28]

Atf is cheap, just not when filling this trans, if I remember correctly dry fill is 14 litres and a change is 9

Valve body is possible to DIY there's a few good write ups by various European and American owners. Not a cake walk but do able.

I've posted the same info to the forum in which they often rebuild stuff like this and I'll see what they say about a rebuild.

Obviously a fluid change is easier so I'd prefer it unless a rebuild is unavoidable. Already have a filter kit with new seals etc so might as well install it. As you said, rarely go bad but if I've got it, it's going in. After 25 years who knows if it's still intact haha

[Eagle 1528]

No way its 14L, more like 10L. You'd only about 4L per drain. How many km on it?.

[Auzeras 28]

Ah I thought I read somewhere it was 14. 210k kms